Self-advancing mine roof supports



1965 R. D. LEE ETAL 3,197,965

SELF-ADVANCING MINE ROOF SUPPORTS Filed Jan. 10, 1961 10 Sheets-Sheet 1 "Fizz.- (imam/lie Wnd W fdwm a/add 2y 294mm 2 72M;

da um u 3, 1965 R. D. LEE ETAL 3,197,965

Aug. 3, 1965 R. D- LEE ETAL SELF-ADVANCING MINE ROOF SUPPORTS Filed Jan. 10, 1961 10 Sheets-Sheet 3 g- 3, 1965 R. D. LEE ETAL 3,197,965

SELF-ADVANCING MINE ROOF SUPPORTS Filed Jan. 10, 1961 10 Sheets-Sheet 4 Aug. 3, 1965 Filed Jan. 10, 1961 R. D- LEE ETAL SELF-ADVANGING MINE ROOF SUPPORTS 10 Sheets-Sheet 5 Aug. 3, 1965 R. D. LEE ETAL 3,197,965

SELF-ADVANCING MINE ROOF SUPPORTS Filed Jan. 10, 1961 10 Sheets-Sheet e u L G @ASCL lO fi R9 QM w xw WWW 2y aldm w Aug. 3, 1965 R. D. LEE ETAL SELF-ADVANCING MINE ROOF SUPPORTS l0 Sheets-Sheet 7 Filed Jan. 10, 1961 WW Q VN/ I I II x I I l A ll m ml llw @N N 3 a 3 1965 R. D. LEE ETAL 3,197,965

SELF-ADVANCING MINE ROOF SUPPORTS Filed Jan. 10, 1961 10 Sheets-Sheet 8 R. D. LEE ETAL SELF-ADVANCING MINE ROOF SUPPORTS Aug. 3, 1965 10 Sheets-Sheet 9 Filed Jan. 10, 1961 Aug. 3, 1965 R. D. LEE ETAL SELF-ADVANGING MINE ROOF SUPPORTS 10 Sheets-Sheet 10 Filed Jan. 10, 1961 W W W idwin/ A m B) fiwm xflw United States Patent 3,197,965 SEIJI ADVANCHJG MINE RUG SUI IOR'IS Roger Demant Lee and Robert Edwin. Harold, Great Sanlrey, Warrington, England, assignors to Eiectro- Hydraulics Limited, Warrington, England, a corporation of the United Kingdom Fiied Jan. 10, 1961, Ser. No. 81,835 11 Qiaims. (Cl. 6I45) This invention relates to self-advancing mine roof supports.

Most existing powered mine roof supports both support and release a given area of mine roof in the. face several times successively before it is finally left behind in the waste. This stressing and de-stressing has an adverse effect on the roof.

The system herein described eifects a considerable improvement by providing that two frames, constituting a roof support and each comprising, for example, a floor skid, and a roof bar (which may be longer than the floor skid) and means, for example, two or more hydraulic jacks for causing movement of the skid and bar toward and away from one another so as to secure the frames in operative position between the floor and roof of a mine, may be moved forward independently step by step a distance equal to twice that moved forward by a conveyor or guide rail for each cycle. By virtue of this, each frame can remain set in one position for two cycles of conveyor or guide rail advance instead of one and so affords improved roof control.

According to the present invention a self-advancing mine roof support comprises twoframes arranged for sliding movement parallel to each other, a hydraulic ram, one element of which is adapted to be connected to an anchorage in the mine, the other element of which is arranged to be held by one or both frames, when in roof supporting position, and amplifying gearing coupling .the said other element to the frames, the arrangement being such that, on the one hand, with one or both frames in roof-supporting position, the anchorage may be moved by movement of said one element, while on the other hand, with the anchorage held and one frame in roof-supporting position, the other frame may be moved by said other element from a position behind to a position in advance of the fixed frame.

The anchorage to which the ram is connected may take any convenient form providing it can be moved in turn after each frame has advanced. Thus the anchorage may take the form of a coal conveyor adapted to be advanced by the ram after advancement of one frame and prior to advancement of the other frame.

In one embodiment of the invention, the said other element, for example the cylinder of the ram, may be hold while the piston of the ram is operated to advance the coal conveyor, a flexible connecting member, for example a rope or chain, anchored to the front end of each frame and passed around a pulley orthe like secured to the said other element of the ram. Alternatively, the said other element may be held by one of a pair of stops, one stop being provided on each frame.

The gearing may also comprise a flexible connecting member, for example a rope or chain, anchored to the rear ends of the frames andpassed around a pulley or the like mounted on said other element of the ram.

Alternatively, the gearing may comprise two racks, one fast with each frame and both meshing with a pinion mounted on said other element of the ram. In this case, the racks and pinion also serve to hold the said other element of the ram while the said one element is extended to advance the coal conveyor.

Preferably, means are provided for mountng the frames "ice for relative movement, for example relative sliding movement, in substantially parallel relationship, and the mounting means may be arranged to allow relative vertical movement between the frames and pivotal movement in a vertical plane of one frame'relative to the other.

A telescopic roof support prop may be provided to afford additional roof support at the waste edge.

The invention is herein described with reference to a coal conveyor, but this term is to be understood also to include guide rails or plates, and it is to be understood that the conveyor may be advanced in a succession of small steps or in one long step before a frame is advanced.

Various forms of self-advancing mine roof supports according to this invention are diagrammatically illustrated in the accompanying drawings, in which:

FIGURE 1 is a top plan view of the self-advancing mine roof supports in different positions for operation;

FIGURE 2 is a view similar to FIGURE 1, but of an alternative form of support;

FIGURE 3a is an enlarged side elevational view of the support shown in FIGURE 1;

FIGURES 3 and 4 are enlarged scale side and end elevational views respectively of the support of FIG- URE 2;

FIGURE 5 is an enlarged scale perspective view of the support of FIGURE 2;

FIGURE 6 is a plan view of one alternative form of support;

FIGURE 7 is a side elevation partly in section of another form of support, showing in detail the manner in which the pulleys secured to the cylinder of the ram may be arranged;

FIGURE 8 is a further view of the construction shown in FIGURE 7, being a part section on the line 88 of FIGURE 9, and shows the manner in which the frames are slidably connected together;

FIGURE 9 is a plan view of the support of FIG- URE 7;

FIGURE 9a is a plan view of a support basically similar to that shown in FIGURES 7 and 9, but incorporating certain modifications; and

FIGURE 10 is a plan view of an additional prop which may be attached to the supports.

Referring to FIGURES 1 and 3a, a roof support comprises two frames D, D, between which a double-acting hydraulic ram having a piston rod element A and a cylinder element B is arranged.

Each frame, which is only diagrammatically illustrated, comprises a floor skid FS and a roof bar RB (shown in FIGURES 1 and 2 in dot and peck lines), which may be longer than the floor skid, and two hydraulically operable jacks G, G, 6,, G respectively; each frame is provided with lugs E by means of which, as will be described below, theframes can be caused to slide along the ram cylinder B or alternatively the ram cylinder can slide with respect to the frames D, D If desired, the roof bars RB of the two frames may be slidably attached to each other. As shown in FIGURE 1, which indicates the various positions adopted by the ram and frames during their operation, the free end of the piston rod element is provided with means indicated at A whereby it is adapted to be attached to the rear surface of a coal conveyor I which, as explained below, When required serves as an anchorage for the piston rod element. The front end of one frame D is attached to the front end of the other frame D, by means of a rope or chain H whilst the rear end of the frame D is attached by similar means H to the rear end of the frame D The ropes or chains H, H pass around a pair of pulley wheels or sheaves C coaxially mounted on an extension formed on the rear end of the ram cylinder 3 B, and are anchored to the frames adjacent the floor, as can be seen most clearly in FIGURE 3a.

In the alternative arrangement shown in FIGURES 2-5 in which similar parts are identified by the same reference numerals as in FIGURE 1, a pulley or sheave C is attached to each end of the ram cylinder B. This alternative, as will be seen, allows the frames D, D to be somewhat shortened, so that each pair of jacks G, G can be brought closer together, thus exposing less roof between the coal face CF and waste edge WE.

The arrangement of the lugs E employed in the embodiments of FIGURES 1 and 2-5, whereby the frames are enabled to slide with respect to each other, can be seen most clearly from FIGURE 5. Thus from this figure it will be noted that the floor skid F5 of each frame is provided with a longitudinally extending angle plate AF, which is fast with the floor skid and to which a lug E is fast, one adjacent the front end of each angle plate. To each side of the ram cylinder B a longitudinally extending channel member CM is fast, each arranged slidably to engage with the lug E on the adjacent frame. It will readily be appreciated that this arrangement provides one simple form of means to allow sliding parallel movement between the frames. In addition, of course, it enables the ram cylinder B to slide relative to. the frames.

As will be seen from FIGURES 1 and 2, it is necessary for the conveyor I to be advanced after the passage of the coal cutting machine (position 2) to a position adjacent to a new coal face as shown in positions 6 and 7 to allow the conveyor to accept coal from the new face. The conveyor will have to be moved from the position 2 at the left-hand side of the drawing forwardly towards the coal face as shown on the right-hand side of the drawing. In position 2 the piston rod A of the hydraulic ram is retracted into the ram cylinder B and the jacks G, G are extended so that the frames D, D are locked between the fioor and roof of the mine. To move the conveyor J forwardlytowards the coal face CF the ram is operated by admitting liquid under pressure into the ram cylinder to cause the. piston and piston rod to move outwardly thereby expanding the ram, The thrust on the conveyor applied by the piston rod A causes the conveyor to be advanced, whilst the ram cylinder B is maintained in its initial position by the chain or rope H attached to the front ends of the frames D, D these, as stated above, being anchored between the roof and floor of the mine. The stages of operation of the hydraulic ram are shown from positions 2-6 inclusive.

When the conveyor is fully advanced, that is to say when the parts are as shown in position 6, the hydraulic pressure supply to the ram is cut off, and the roof jacks G are released so that the frame D can be drawn forward. To enable this to be done, hydraulic pressure is admitted to the other side of the ram piston thereby allowing the ram cylinder B with its pulleys or sheaves C to be advanced, the conveyor being maintained in its position at 6 by other rams on adjacent self-advancing mine roof supports. Advancement of the sheaves C causes through the rope or chain H attached to the rear ends of the frames, advancement of the frame D and clearly since the end of the rope H attached to the rear of the frame D is fixed, this frame being fixed between the roof and floor of the mine, it follows that the end attached to the rear end of the frame D must move twice the distance moved by the pulley C so that the frame D is advanced twice the distance moved by the ram cylinder resulting in the frame D stepping past the frame D from a position behind this frame to the position in advance of it shown at 7. Thereafter the hydraulic jacks G are extended and the roof bar thus re-tightens against the roof.

. The operation, of course, is repeated when necessary by releasing the jacks G on the next cycle of conveyor advancement so that the frame D steps past the frame D Referring to FIGURE 6 a self-advancing mine roof support unit is shown in plan with the roof bars removed and comprises two frames, each again including a floor skid and roof bar, a front and rear hydraulically operated jack. The floor skids are shown at 1, Ta and the hydraulic jacks at 2, 2a, 3, 3a respectively. The floor skid of each frame is provided with a guide rod 4, 4a fixed to bars 5, s, 511, at: which also carry racks 7, 7a. Guide members 23 connected by a central section 26 are slidably disposed on the guide rods. The cylinder element 8 of the advancing ram is connected by an extension ill to the central portion 25 and the piston rod element at 3, as in the previous arrangement is fast with a conveyor, not shown. Meshing with the racks 7, 7a is a single pinion It rotatably mounted on the central section 26. The relative thickness of the pinion It and the width of the toothed faces of the racks 7, 7a are preferably such that engagement is maintained between them during vertical displacement of one frame relatively to the other.

The cycle of operation is as follows:

The jacks 2, 3, 2a, 3a of each frame are extended so that the roof bar of each frame is forced into the roof supporting position. 'Thereafter the piston rod 9 of the ram is extended so as to cause advancement of the convey-or to the coal face.

The jacks 2, 3: of the rear frame are then released and the ram retracted. As the ram piston rod 9 is fixed to the conveyor which itself is fixed as described above by the rams of adjacent frames, the cylinder S moves over the rod 9 to close the ram, and during this retraction of the ram, the pinion 10 is rotated because it is in engagement with the rack 7a of the locked frame which is secured between the floor and the roof of the mine. Since the other rack 7 is also meshing with the pinion, the rotation of the pinion will cause the rack 7 to advance taking the rear frame with it. The total advancing movement imparted to the rear frame comprises that due to rotation of the pinion and that due to the advance of the pinion through closure of the ram. Thus the total advancement amounts to twice the advance of the cylinder of the ram resulting in the rear frame stepping from a position behind to a position in front of the fixed frame.

The jacks 2, 3 are then extended so that the frame again suports the roof. After a further pass of the coal cutting machine, the conveyor is advanced as before by extension of the ram. The frame which has previously remained locked is now released from supporting the roof and the ram closed to advance the said frame to the conveyor, the hydraulic jacks of that frame then being extended so that the said frame is once again supporting the roof.

It will be appreciated that each frame, in advancing, moves from a position in the rear'of the other frame, to a position in front of the said other frame, thereby avoiding repeated stressing and destressing of the roof.

Referring now to FIGURES 7, 8 and 9 each frame has two jacks 2t 21, a roof bar 22 and a floor skid 23 each of which floor skids is secured a guide rod 24. The piston rod element 33 of a ram comprising. also a cylinder element 25 is provided at its outer end with means 34 by which the rod element 33 can be connected to an anchorage, eg a coal conveyor 1. To the cylinder element 25 of the ram is secured a guide device which comprises a central section 26, in which are mounted two pulleys 2'7, and two guide members 28, pivoted at 29 to the central section 26 and being slidable on the guide rods 24. will thus be seen that the guide members 28 can pivot or rotate in a vertical plane with respect to the section 26. As shown, flexible connections H and H pass around the two pulleys 27, one H being fixed to the rear ends and the other, H, to the front ends of the skids, so that the coal conveyor can be advanced and the advance of the frames obtained in exactly the same manner as that described with reference to FIGURES 1-5.

Instead of providing a flexible connection H extending between the front end of each skid and passing around a pulley to enable the ram cylinder to be held when its piston rod is extended to advance the conveyor, this connection and its associated pulley may be omitted and its function performed by a pair of adjustable stops 30 as shown in FIGURE 9a. The adjustable stops comprise for example collars, adapted to be adjustably fixed to the guide rods 24- of each frame. The stops 3t) perform the function of holding the ram cylinder 25 when its piston rod 33 is extended to advanw the conveyor by providing an abutment for one or both the guide members 28.

When, as is intended normally to be the case, while in root supporting position, the frames of each unit are arranged in staggered formation as shown, and when the time comes to advance one frame, it is advanced to the fullest possible extent, i.e. from a position behind to a position in front of the other, then only one stop will be operative at any one time.

Thus, with the frames in the position shown in FIG- URE 9a, should the ram piston be extended to advance the coal conveyor, the cylinder will be held, that is to say the thrust of the ram will be reacted, by the guide member 28 on the guide rod 24 of the foremost frame abutting the stop 30 thereon, the guide member 28 in this instance being positioned at the rear end of the guide rod 24. The foremost frame, while this is occurring, will of course be fixed in roof supporting position. The rear frame will also normally be in roof supporting position, but with this particular arrangement will not play any part in holding of the ram cylinder. Thus it will be seen that the stops 30 alternately serve as an abutment for one or other of the guide members 28.

\Vhen, on the other hand, the frames are not arranged in staggered formation, i.e. are arranged in line with each other when in roof supporting position, or are not required to be advanced to the fullest possible extent, this will result in the guide members 28 being in a position intermediate the ends of the guide rods 24. In this case, the stops 3%) will have to be moved along the guide rods and fixed in a new position adjacent the guide members 28 to serve as abutments therefor. So long as the frames are not in exact alignment when the conveyor is advanoed, then, as before, the stops will be alternately operative to hold the ram cylinder, but when the frames are in alignment it will normally be arranged that both stops function together. This could, of course, be arranged regardless of the relative positions of the frames, but would entail the inconvenience of having to re-position the stops each time advance of the frames and conveyor was required.

From the above it will be appreciated that whereas in the other embodiments described herein in which the means for holding the ram cylinder comprise a flexible connecting member and pulley, or racks and a pinion, it is necessary for both frames to be fixed in roof supporting position for the holding means to be operative, with the provision of adjustable stops it is only essential for one frame to be fixed in roof supporting position.

Under certain circumstances it may be found desirable to provide an additional support to the mine roof at the waste edge WE. This can readily be done by providing a single telescopic hydraulically operated prop as shown in FIGURE 10. Thus there is provided a telescopic hydraulically operated prop 31 carried by a horizontal member or members 32 secured to the section 26 (see FIG- URE 8) or directly to the cylinder 8 (see FIGURE 6), or the cylinder 25 (see FIGURES 7-9) of the advancing ram. It will also be clear that the said additional prop 31 can be fitted in a similar manner to the advancing ram in any of the constructions shown in FIGURES 1-5. The connection of the additional prop 31 to the section 25 or the cylinder 8 or the cylinder 25 may be such as to allow for limited movement of the prop 31 with respect to the said sections or cylinder.

It will, of course, be appreciated that the additional prop 31, when fitted, is released from supporting the roof before movement of the cylinder of the advancing jack, since such movement will be imparted to the prop 31.

What is claimed is:

1. A mine roof support for use in a mine having an anchorage therein, said support comprising two alternately advanceable frames, each said frame including a floor skid, a roof bar, and means for causing movement of said floor skid and said roof bar towards and away from one another so as respectively to release and to secure said frames from or in an operative position between the floor and roof of the mine in which operative position said frame is held stationary by engagement of its floor skid and roof bar respectively with the floor and roof of the mine; a double acting hydraulic ram having a cylinder element and a piston rod element; means mounting said frames to slide relatively to one another in spaced parallel relationship toward and from said anchorage and connecting said frames to one of said elements for movements relative thereto; means for operatively connecting the other of said elements to said anchorage; and motion transmitting and amplifying means positioned between said frames and being connected to said one of said elements and to both of said frames and being operable, when one of said frames is held stationary in its operative position, the other of said frames is in released position and said one of said elements is operated relatively to said other of said elements for moving said other of said frames an amount greater than the operating movement of said one of said elements.

2. A mine roof support operable to advance a coal conveyor towards a coal face comprising two frames each including a floor skid, a roof bar, and means for causing movement of said skid and bar towards and away from one another so as respectively to release and to secure said frame from or in an operative position between the floor and roof of a mine in which operative position said frame is held stationary by engagement of its skid and bar respectively with the floor and roof of a mine; mounting means which mount said frames to slide relatively to one another; a double act-ing hydraulic ram including a cylinder element and a piston rod element; means connecting one of said elements to said coal conveyor; means to hold the other of said elements against movement relatively to said frames in a direction away from said coal conveyor when at least one of said frames is in operative position, whereby extension of said one of said elements when said one of said frames is held stationary in operative position causes advancement of the coal conveyor; and motion transmitting means positioned between said frames and being connected to said other of said elements and to both of said frames and being operable for moving a first of said frames relatively to the second of said frames and said conveyor when said first of said frames is in released position, said second of said frames is held stationary in its operative position and said other of said elements is operated relatively to said one of said elements.

3. A mine roof support as claimed in claim 2 in which the means to hold said other of said elements against movement relatively to said frames in a direction away from said coal conveyor when both said frames are in operative position comprises a first flexible connecting member anchored to the front ends of the frames, and a first pulley mounted on said other of said elements and around which said first flexible member passes, and in which said motion transmitting means comprises a second flexible connecting member anchored to the rear ends of the frames and a second pulley mounted on said other of said elements and around which said second flexible member passes.

4. A mine roof support as claimed in claim 2 in which the means to hold said other of said elements against movement relatively to said frame in a direction away from said coal conveyor when said one of said frames enemas is in operative position comprises two stops, one adjustably mounted on each frame to provide an abutment for said other of said elements.

A mine roof support as claimed in claim 2 in which said mounting means comprises a guide bar connected to each of said frames, and cooperating guides connected to said other of said elements and receiving said guide bars, whereby to permit relative vertical movement between the frame 6. A mine roof support as claimed in claim 2 in'which said mounting means includes means coupling said frames for pivotal movement in a vertical plane of one frame relative to the other.

'7. A mine roof support as claimed in claim 2 including a telescopic roof support prop connected to and in the rear of said other of said elements, said prop providing additional roof support at the mine waste edge.

8. A mine roof support operable to advance a conveyor toward a coal face comprising two frames each including a floor skid, a roof bar, and means for causing movemerit of said skid and bar toward and away from one another so as respectively to release and to secure said frame from or in an operative posi ion in which operative position said frame is held stationary by engagement of its skid and bar respectively with the floor and roof of the mine; a double acting hydraulic ram including a cylinder element and a piston rod element positioned between said frames; means mounting said frames to slide relatively to one another in space parallel relationship toward and from said conveyor and connecting said frames to one of said elements for movements relative thereto; two racks, one fast with each of said frames; a pinion rotatably mounted on said one of said elements and meshing with said racks respectively on opposite sides of said pinion; and means for connecting the other of said elements to said conveyor, said racks and pinion serving to hold said one of said elements against movement when both of said frames are held stationary in their operative positions whereby movement of said other of said elements will move said conveyor; and said racks and pinion begin operable to move one of said frames relatively to the other of said frames and to said conveyor when said one of said elements is operated-while said one of said frames is in released position and the other of said frames is held stationary in operative position.

9. A mine roof support for use in a mine having an anchorage therein, said support comprising two alternately advanceahle frames, each said frame including a floor skid, a, roof bar, and means for causing movement of said floor skid and said roof bar toward and away from one another so as respectively to release and to secure said frame from or in an operative position between the floor and the roof of the mine in which operative position said frame is hel stationary by engagement of its floor skid and roof bar respectively with the floor and roof of the mine; a single hydraulic ram having a cylinder ele- 10 merit and a piston rod element; means mounting said frames to slide relatively to one another in spaced parallel relationship toward and from said anchorage and connecting said frames to one of said elements for movements relative thereto; means for operatively e on-ecting the other of said elements to said anchorand motion transmitting and amplifying means positioned between said frames and being connected to said one of said elements and to both said frames and being operable when one of said frames is held stationary in its operative position,.the other of said frames is in released position and said one of said elements is operated relatively to said other of said elements, for moving said other of said frames an amount greater than the operating movement of said one of said elements. 10. A mine roof support according to claim 9 in which said motion transmitting and amplifying-means comprises a flexible connecting member anchored to the rear ends of said frames; and a pulley mounted on said one of said elements and around which said flexible member passes. 3O 11. A mine roof support according to claim 9 in which said motion transmitting and amplifying neans comprises two racks, one fast with each of said frames; and a pinion rotatably mounted on said one of said elements and meshing with said racks respectively on opposite sides of said pinion.

References Cited by the Examiner FOREIGN PATENTS 148,217 9/52 Australia. 1,164,448 5/58 France. 1,245,142 9/60 France. 1,249,920 11/60 France. 1,080,497 4/ 60 Germany. 1,090,159 10/60 Germany.

CHARLES E. OCONNELL, Primary Examiner.

JACOB L. NACKENOFF, JACOB SHAPIRO,

' Examiners. 

1. A MIND ROOF SUPPORT FOR USE IN A MINE HAVING AN ANCHORAGE THEREIN, SAID SUPPORT COMPRISING TWO ALTERNATELY ADVANCEABLE FRAMES, EACH SAID FRAME INCLUDING A FLOOR SKID, A ROOF BAR, AND AMEANS FOR CAUSING MOVEMENT OF SAID FLOOR SKID AND SAID ROOF BAR TOWARDS AND AWAY FROM ONE ANOTHER SO AS RESPECTIVELY TO RELEASE AND TO SECURE SAID FRAMES FROM OR IN AN OPERATIVE POSITION SAID FLOOR AND ROOF OF THE MINE IN WHICH OPERATIVE POSITION SAID FRAME IS HELD STATIONARY BY ENGAGEMENT OF ITS FLOOR SKID AND ROOF BAR RESPECTIVELY WITH THE FLOOR AND ROOF OF THE MINE; A DUBLE ACTING HYDRAULIC RAM HAVING A CYLINDER ELEMENT AND A PISTON ROD ELEMENT; MEANS MOUNTING SAID FRAMES TO SLIDE RELATIVELY TO ONE ANOTHER IN SPACED PARALLEL RELATIONSHIP TOWARD AND FROM SAID ANCHORAGE AND CONNECTING SAID FRAMES TO ONE OF SAID ELEMENTS FOR MOVEMENTS RELATIVE THERETO; MEANS FOR OPERATIVELY CONNECTING THE OTHER OF SAID ELEMENTS TO SAID ANCHORAGE; AND MOTION 